* They are large polymers. Polymers are long chains of repeating subunits called monomers.

* They are built from a limited number of monomers. While there are many different macromolecules, they are all built from a relatively small number of monomers. For example, carbohydrates are built from sugars, proteins are built from amino acids, and nucleic acids are built from nucleotides.

* They are essential for life. Macromolecules play a wide variety of essential roles in living organisms, including providing structural support, storing energy, and carrying out chemical reactions.

In addition to these common features, macromolecules also share some common characteristics in terms of their formation and breakdown:

* They are synthesized through dehydration reactions. In dehydration reactions, a water molecule is removed to link monomers together.

* They are broken down through hydrolysis reactions. Hydrolysis reactions add a water molecule to break the bond between monomers.

Here's a summary table:

| Feature | Description |

|---|---|

| Size | Large polymers |

| Monomers | Built from a limited number of repeating subunits |

| Function | Essential for life |

| Formation | Dehydration reactions |

| Breakdown | Hydrolysis reactions |

Understanding these common features helps us appreciate the fundamental importance of macromolecules in all living organisms.